The invention is in the field of air treatment apparatuses and equipment for commercial and residential buildings. These include systems for filtering the air, passing the air through bactericidal ultra-violet light paths, and adding a bactericide or air freshener to the air. This can be done in a number of ways. Different modes of achieving these ends are set forth in the following U.S. Patents.
Generally larger systems, which use liquid air freshener or bactericide, and many of which comprise stand-alone units with others incorporating spray means for conditioning the air, are set forth in U.S. Pat. Nos. 4,078,891; 3,044,276; 3,490,436; 3,733,060; 5,030,253; 3,576,593; 4,268,285; and 4,601,886.
A stand-alone purification system utilizing ultra-violet light and filtering is described in U.S. Pat. No. 3,744,216.
A complicated system for dispersing solid pellets and then ventilating them with an air stream is illustrated in U.S. Pat. No. 3,418,068.
The two devices known to applicants which are most related to their invention are described in U.S. Pat. Nos. 3,930,797 (Issued Jan. 6, 1976, to Albert E. Gertz) and 4,067,692 (Issued Jan. 10, 1978, to Richard W. Farris).
The first of these comprises a container disposed inside an air passageway with an openable door into which is put some kind of air treating substance. When the substance is exhausted, it is replaced by opening a small door accessible from outside the passageway. The chamber has a permanent set of pass-through apertures so that once inside the air passageway, whatever dispersant is within the container is dispersed uniformly until it is totally dissipated.
The second of these disclosures also pertains to a unit which is mounted to the wall of an air passageway. This unit provides for variable communication between a dispersant and an air passageway by means of rotating disks with apertures which move into varying degrees of misalignment or alignment, thereby regulating the amount of scent which reaches the air passageway.
None of these provide a relatively simple system, utilizing inexpensive modern electronic control technology, for exposing a dispersant to the air stream within an air passageway of an air conditioning or heating system in a controlled and programmable fashion.